Palyno-stratigraphy of the sedimentary formations of Assam: 1. Stratigraphical positions of the Cherra formation

Abstract

Palynological studies are being pursued in the South Shillong region, to explore the possibility of resolving the probable age and stratigraphical position of the Cherra sandstone stage, which still seems to be a matter of controversy. The present paper presents the result of a preliminary investigation on a number of samples belonging to different levels of the Cherra formation. The rich miofloral assemblage contained within the samples is not only rich in angiospermic pollen grains but also shows great diversity in species. The spores are comparatively poorly represented, though one of the forms usually predominates in number. Certain clements in the palynological assemblage studied so far, though not yet conclusive, provide some evidence which points towards a lower Eocene age for the Cherra formation. However field evidences clearly indicate that the Cherra formation is part of the overlying Eocene succession rather than the underlying Upper Cretaceous succession.